Process of creasing and folding paper



(No Model.) 2 Sheets-Sheet 1..

F. H. RICHARDS. PROCESS OFGREASING AND FOLDING PAPER.

N0. 366,188. Patent ed July 5, 1887.v

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P. H. RIGHA PROCESS OF GBEASING AND ING PAPER. NO. 366,188,. Patented July 5, 1887.-

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UNITED STATES PATENT Urrrcn.

FRANCIS H. RICHARDS, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO THE PRATT & WHITNEY COMPANY, OF HARTFORD, CON- NEOTIGUT.

PROCESS OF CREASING AND FOLDING PAPER.

SPECIFICATION forming part of Letters Patent No. 366,188, dated July 5, 1887.

Application filed November 15, 1886. Serial No. 218,871. (No model.)

To aZZ whom it may concern.-

Be it known that I, FRANCIS H. RICHARDS, a citizen of the United States, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented certain new and useful Improvements in Processes of Ureasing and Folding Paper, of which the following is a specification.

This invention relates to the manufacture of envelopes and similar articles, the blanks for which are creased in the folding lines previous to folding, the object being to produce of folded paper such articles having smooth unbroken edges.

To this end the invention consists in the improved method or process of creasing and folding the paper, as hereinafter more fully set forth.

In the drawings accompanying and forming a part of this specification, Figure 1 represents in edge view, and greatly exaggerated, a plain sheet of paper. Fig. 2 represents the same after creasing before folding. Fig. 3 represents the creased sheet folded over. Fig.v 4 represents a sheet folded in the old way without creasing. Figs. 5, 6, and 7 respectively illustratethreestages of the creasing operation.

Similar characters designate like parts in all the figures.

The kinds of paper of which envelopes are very generally manufactured consist, essen tially, of three parts-nan1ely, the two surface layers, highly sized, and an intermediate more loosely-formed central layer. In Figs. 1 to 41, inclusive, I have distinguished these layers by differently shading them, and have designated them as follows: B and D respectively designate the upper and lower surface layers, while 0 designates the central layer. In Figs. 5 to 7, inclusive, the entire sheet is designated by A.

My improved process is intended especially for treating that class of paper, and to produce in the same at the folding line during the creasing operation a sliding of one surface layer with respect to the other, at the same time partially re-forming the central layer, all in such manner that the surplus material shall in folding the sheet be thrown within the fold, and thus avoid straining and cracking the outer layer. For accomplishing this result I submit the sheet to be creased to the action of suitable creasing-dies while under-tension. This operation is performed by means of dies which forcethe paper into differcut and substantially parallel planes joined by short reverse curves. These curves are shown at 12 and 14 in Fig. 2, 20 and 21 being the different planes joined by said curves.

In the drawings said dies are shown in 6Q crosssection, the lower one being designated by M and the upper one by N. I consider them most effective when constructed of the shape substantially as shown-that is to say, having the oppositely-disposed corners 7 and 6 5 8. They are supposed to be operated by meansof some suitable mechanism,which may be the sameshown and describedin my United States Patent No. 343,854, dated June 15,1886.

As a means for producing the requisite tension in the sheet While creasing, any convenient method or apparatus suitable therefor may be employed. One such method consists in clamping the edge of the sheet between fixed bed and a part held thereon by a springpressure. If designates such a bed, having a fixed position in the creasing mechanism. S designates a spring of any suitable construction, it being affixed tosaid bed, or to some other part, by a screw, 3, or similar holding 8o device.

The operation of the apparatus is as follows: The dies being opened, as in Fig. 5, the sheet, A, to be creased is laid between them, with one edge, 4, under spring S. The other edge, 5,is supposed to be extended toward the right hand and held in a similar manner by duplicate or equivalent devices. Upper die, N, is now brought down onto the paper, forcing it down on lower die, M,-as in-Fig. 6. This 0 draws the edge of the sheet from under spring S, away from line 01 cl, the distance 6, and bends the sheet over the corners 7 and 8 of the respective dies. Next the die M is forcibly moved laterally toward die N, as may be seen by comparing with dotted line a a, bringing the paper against corner 7 with a considerable pressure, and drawing it from under sprin g S the further distance 9.

The effect of this operation is illustrated in. too

ii fil original positions on layers 13 and D. While- 5 the part 12 oflayer D is forced into die M,

the part 14 of layer B is drawn up by the tension of spring S, producing the distorted arrangement of lines 10. On completingthe fold, as shown in Fig. 3, part 12 remains as in IO Fig. 2, while in the part 14 the curve is reversed, and layer B is there doubled under into one or more irregular folds, as 15, which is thus inclosed and hidden from sight between the upper and lower parts of the sheet.

15 In this way the layer D remains throughout ofsubstantially its original length and character, and forms the smooth exterior of the folded edge.

By the old inode of folding, the inner layer,

20 B, retained more nearly its normal length and condition, while the outer layer, D, sustained the strain and consequent'injury necessarily incident to being forcibly folded without special preparation therefor. The result was to 25 break the outer layer and produce a more or less ragged surface-as, for instance, at 16, Fig. 4. Envelopes thus made of the comparatively brittle paper commonly used therefor present, when packed in boxes, a'fuzzy and objection able surface, while those made of the same 0 grades of paper creased by my newly-invented process present a smooth and in every way a more desirable appearance.

Having thus described my invention, I claim- 1. The improved method or process of creasing paper, which consists in forming therein reverse curves while the sheet is under tension, substantially as set forth.

2. The improved method or process of foldo ing paper, which consists in forming at the folding-line reverse curves while the sheet is under tension, and then reversing one of said curves, whereby the fold is completed and the surplus material is thrown within the fold, 5 substantially as set forth.

FRANCIS H. RICHARDS.

Witnesses:

WILBUR M. STONE, GEO. A. REYNOLDS. 

